Flexible tooling apparatus

ABSTRACT

A flexible tooling system includes a support table with multiple openings adapted to removably accept a self-contained actuator. Each opening of the support table provides vacuum and air supply lines as well as a bus interface so that each position may be uniquely addressed and commanded separately from any other openings. The self-contained actuator has corresponding connectors for receiving the vacuum and air supply as well as for interfacing with the bus. An actuator may be placed at a particular location by insertion into the receptacle at the opening in the support table aperture. The actuator may be commanded to raise, lower, lock in position and supply vacuum separate from any other actuator.

BACKGROUND OF THE INVENTION

This invention relates to machine tools and more specifically to aflexible tooling apparatus for providing a support deck for use withmachine tools or assembly tools for processing materials.

When machining material with machine tools or assembly material forfastening, it is necessary to provide a support system for the materialbeing machined or operated upon. In the past, such supports havecomprised a tooling support which substantially conforms to thethree-dimensional shape of the part or item being processed. The design,fabrication and storage of such tooling supports can become prohibitive.A separate tooling support is required for each uniquely shaped itembeing processed. Often the setup time and effort to prepare and positionthe tooling die becomes greater than the time involved in actualmachining or processing of the part.

To resolve some of the drawbacks of the fixed tooling die situation,variable tooling supports have been developed, for example, as describedin U.S. Pat. No. 5,372,357, wherein a plurality of spaced supports areprovided in fixed relation to one another and the supports are adjustedheightwise to support the workpiece at certain points. The workpiece isthen either clamped to the supports or the supports provide some sort ofclamping through the use of vacuum at the suction cups, for example.

Heretofore, these systems have been quite expensive and complex with alarge number of interactions required to provide the appropriate controland power to cause the raising and lowering, as well as the applicationof vacuum to each of multiple support members. Variable systems whichallow movement of the support stanchions in a horizontal plane, as wellas the vertical extension thereof, provide even further difficultiesgiven that control wires, power wires and hydraulic or pneumatic orvacuum supply lines are required to also be movable. Maintenance costsrelated to such systems can be quite high. Over the useful life of suchan apparatus, the potential for failure of electrical connections, forexample, becomes greater with each successive movement.

Further, the cost of such systems is out of the reach of many businessesand such a system may be overly complex for small business applications.

SUMMARY OF THE INVENTION

In accordance with the present invention, a flexible tooling system isprovided wherein a support table has a plurality of apertures thereinwherein said apertures are adapted for receiving a self-containedactuator therewithin in removable relation. Each position of the supporttable provides a vacuum and air supply line as well as a bus or networkinterface so that each position may be addressed separately. Theremovable actuator has corresponding connectors for receiving the vacuumand air supply as well as for interfacing with the bus, each positionhaving a unique address so that an actuator may be placed at aparticular location by insertion into the receptacle at the tableaperture and subsequent securing thereto. The actuator may then beaddressed on the bus to command the actuator to raise, lower, lock inposition and supply vacuum.

It is accordingly an object of the present invention to provide animproved flexible tooling support system.

It is a further object of the present invention to provide an improvedflexible tooling support system which allows easy removal andrepositioning of support actuators.

It is a further object of the present invention to provide an improvedflexible tooling system wherein individual actuators are passively movedto an appropriate position and then locked into place.

It is yet another object of the present invention to provide an improvedflexible tooling system wherein individual actuators are activelyoperable to position themselves to a precision position.

It is a further object of the present invention to provide an improvedflexible tooling system with active positioning with a non-servotechnology.

The subject matter of the present invention is particularly pointed outand distinctly claimed in the concluding portion of this specification.However, both the organization and method of operation, together withfurther advantages and objects thereof, may best be understood byreference to the following description taken in connection withaccompanying drawings wherein like reference characters refer to likeelements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a flexible tooling system with arepresentative part positioned thereon;

FIG. 2 is a top view of a support table section;

FIG. 3 is a sectional view of the table of FIG. 2 taken along line 3--3of FIG. 2 illustrating placement of actuators in relation to the tablewhen in retracted position;

FIG. 4 is a sectional view of the table of FIG. 2 taken along line 4--4illustrating the placement of a plug in the table aperture where anactuator is not presently positioned;

FIG. 5 is a cross-sectional view of a typical passive actuator;

FIG. 6 is a more detailed cross-sectional view of a portion of theactuator of FIG. 5 illustrating the locking mechanism for securing anindividual actuator in position once the desired position has beenobtained;

FIG. 7 is a more detailed cross-sectional of view the lower portion ofthe actuator of FIG. 5 illustrating a hydraulic intensifier used inconjunction with the locking mechanism of FIG. 6;

FIG. 8 is a top view of the actuator of FIG. 5, illustrating the variousconnections to an individual actuator;

FIG. 9 is a flow chart of operational steps employing the flexibletooling system;

FIG. 10 is a partial cross-sectional view of an actuator according to anembodiment of the present invention employing active positioning;

FIG. 11 is a top view of the cylinder body of the actuator of FIG. 10;

FIG. 12 is a top view illustrating the specific connections provided inthe table for receiving the actuator;

FIG. 13 is a side view illustrating features of the actuator receivingsite of an actuator table according to the present invention;

FIG. 14 is a side view of a portion of a table with actuators installedthereon, illustrating an extension mount employed with the presentinvention;

FIG. 15 is a top view of the extender of FIG. 14 as installed on anactuator table, illustrating the placement and positional movementsthereof;

FIG. 16 is a block diagram of a typical system employing the activeactuators of the present invention; and

FIG. 17 is a diagram illustrating the pneumatic/hydraulic circuits whichenable extension/retraction and other operations by the actuator as wellas clamping of the clamp body member.

DETAILED DESCRIPTION

Referring now to FIG. 1, a perspective view of a section of a supportsystem according to the present invention with a part supported thereon,the flexible tooling system comprises a table portion 12 which ismodular in construction so as to enable plural table portions 12 to beplaced adjacent one another to provide variable size support surfaces.The table portion 12 is substantially rectangular and includes threepositioning slots 14 at the bottom thereof which extend substantiallyfrom one edge of the table portion to an opposing edge. The slots matewith corresponding guide members 16 which are located as appropriate ata work site to enable the table portion 12 to be precisely positioned byplacement on top of guide members 16. Table portion 12 also includes anelectrical interface 18 which supplies electrical power as well asaddressing information to each of plural positions for actuatorplacement. The actuators 20 are arranged in spaced relation as mountedin actuator holes 22 in table portion 12. The actuator holes may bespaced in alternating offset rows or may also be provided in regularrows, as illustrated in FIG. 1, and provide mounting points wherein anactuator 20 may be inserted into a mounting hole 22 and secured to thetable by any suitable means, for example, bolting. The part 24 beingmachined or otherwise worked sits atop actuators 20 which provide avariable height surface for supporting the part. Each actuator may beextended or retracted vertically along axis 26 to provide variableheight surfaces. The cooperation between multiple actuators and theirvaried adjustment heights provides a support surface that conforms tothe contour of the part. Note that it is not necessary that the part besupported by the actuators over a continuous surface, but that providingvarious support points is sufficient.

While the table 12 as illustrated in FIG. 1 carries actuators in each ofactuator holes 22, the system is such that actuators need not be presentin each of the holes 22. Accordingly, table 12 need not be fullypopulated with actuators, providing reduced cost and flexibility.

Referring to FIG. 2, which is a top view of support table 12 with noactuators placed therein, the alternating row patterns of the supportholes 22 may be observed. More than one support table 12 may be placedadjacent each other in end-to-end or side-by-side relation to provide avariable sized tooling bed.

Referring now to FIG. 3, which is a cross-sectional view taken alongline 3--3 of FIG. 2, illustrating a support table with two actuatorstherein, it may be observed that the table comprises an upper tableportion 28 which has apertures 22 defined therein as well as a lowertable portion 30 which is in spaced relation below upper table portion28. A liner 32 defines a space between upper table portion 28 and lowertable portion 30 and substantially seals the inner volume between thetwo table portions against entry of contaminants and the like. The linermay typically be a polyurethane cup. An actuator 20 is secured to lowertable portion 30 and extends therebelow with the substantial portion ofthe actuator components being below lower table portion 30 as discussedhereinbelow. The portion of the actuator that extends above tableportion 30 further extends into a well defined by liner 32 and mayinclude an end-effector 34 mounted thereto, which may be, for example,as described in co-pending U.S. patent application Ser. No. 08/077,552entitled END EFFECTOR, now U.S. Pat. No. 5,427,363. When the actuator isin a retracted position, the well has sufficient depth such that theend-effector 34 does not extend above the plane of table top portion 28.

For table apertures 22 which do not currently have an actuator installedthereon, a plug member 36, illustrated in FIG. 4 in cross section, isinserted into aperture 22 to seal the interior portions of the tableagainst entry of contaminants as well as to prevent contaminants frompassing through the bottom portion 30 of the table into the spacetherebelow.

Referring now to FIG. 5, a cross-sectional view of a typical passiveactuator, the actuator 20 comprises a main housing portion 42 whichincludes an upper flange area 44 for engaging with lower table portion30 (FIG. 3). The main housing 42 is long in relation to its diameter,for example in a particular embodiment the main housing is approximately24 inches long, while approximately 21/2 inches diameter. The housing issubstantially hollow and receives a cylinder rod 46 in close fitting butsliding engagement with the interior of the housing. The cylinder rod issubstantially surrounded near the upper portion of the main housing by alocking member 48, which is described in greater detail with referenceto FIG. 6 hereinbelow. At the lower extent of cylinder rod 46, an aircylinder piston 50 is provided as described in greater detail withreference to FIG. 7 hereinbelow. Attached to the lower end of housing 42is hydraulic intensifier 52, again, described in greater detail withreference to FIG. 7 hereinbelow. Mounted below the hydraulic intensifierare actuator valves 36, 38 and 40 which are operative to control theextension, retraction, locking and vacuum/positive air pressureapplication of the individual actuator internally. A hydraulic supplyline 54, shown in phantom, extends from intensifier 52 up to lockingmember 48 via an internal portion of the body of the intensifier and themain housing, enabling a system with no external plumbing and hence nohoses or fittings to leak. In operation, the intensifier 52 is suppliedair pressure and employs a relatively low pressure pneumatic input tointensify and create a much higher pressure hydraulic supply forgoverning operation of the clamping member 48.

The actuator is deemed passive because it relies on outside means toaccurately set the height of the actuator, for example, a machine toolas discussed in conjunction with FIG. 9 hereinbelow.

With reference to FIG. 6, which is a more detailed cross-sectional viewof the upper portion of the actuator housing and components therewithin,it may be observed that a locking sleeve 56 substantially surroundscylinder rod 46. The locking sleeve may be securely engaged to the mainhousing by threading 58, for example, which is suitably provided in arecessed portion of the main housing. In a preferred embodiment, thelocking sleeve is held in place with a retaining ring 69 (illustrated inphantom in FIG. 7), to assure that the sleeve does not come loose. Thelocking sleeve is substantially annular in shape and includes a thinannular clamping portion 60 which is adjacent cylinder rod 46 at leastalong an extent thereof. In the area where portion 60 is adjacentcylinder rod 46, a space 62 is defined wherein the space 62 receiveshydraulic fluid therewithin. Accordingly, when pressure is applied tothe hydraulic fluid 64, the locking sleeve portion 60 is caused todeform inwardly so as to firmly engage the rod 46, thereby preventinglongitudinal movement of the cylinder rod. A spacer 66 is provided tosubstantially fill the majority of the volume of the aperture 62 so asto enable a minimal amount of hydraulic fluid to be necessary forcausing deformation of portion 60. A purpose of spacer 66 is tocompensate for the compressibility of the hydraulic fluid 64, since thevolume of fluid is substantially reduced by the presence of the spacer.Upper and lower O-rings 68 and 70 provide seal between locking sleevemember 56 and the main housing, while O-ring 72 provides a seal for theretraction air pressure. It will be understood that cylinder rod 46 issubstantially hollow within the interior. In an alternative embodiment,clamping portion 60 is in tight (interference fit) engagement withcylinder rod 46 in the absence of hydraulic pressure, and is caused tounclamp when hydraulic pressure is applied, thereby assuring that anactuator does not become unlocked on loss of hydraulic pressure.Further, an individual actuator (or the entire bed of actuators) can bedisconnected from the various utilities (air, electric, control) andmaintain the desired extension position. Such a configuration enables,for example, the system to be set up in a given place, and transportedand used at another location.

Referring now to FIG. 7, a more detailed cross-sectional view of thelower portion of actuator 20 illustrating the hydraulic intensifier usedin conjunction with locking mechanism 48, as well as the placement ofthe operation valve, the intensifier body 52 mounts adjacent the lowerportion of actuator housing 44. The intensifier comprises a piston rod76 which is received by piston bore 78 centrally of the intensifierbody. The piston 76 is relatively small in diameter compared to theoverall diameter of the intensifier body. Intensifier piston 76 isslidably movable within cavity 78 and moves inwardly and outwardly inthe cavity with movement of intensifier piston 84. Intensifier piston 84is substantially larger than intensifier piston 76 and is slidablymovable with piston bore 90, which is of fairly large diameter relativeto the diameter of intensifier body 52. Both pistons 76 and 84 haverespective piston seals 82 which enable movement of the piston withinthe piston bore while preventing loss of pressure around the outer edgeof the piston. Piston 76 is mounted to and moves in conjunction withmovement of piston 84 and is operative such that movement of the largepiston 84 results in movement of the smaller piston 76. Since piston 76fits within a much smaller bore 78, the relatively low pressure movementof piston 84 is intensified to a relatively high pressure within pistonbore 78. Piston bore 78 is suitably filled with a hydraulic fluid and isin fluid communication with the chamber 62 surrounding the clampingportion 60 of clamping member 48.

Air pressure is supplied to operate piston 84 upwardly and downwardlyvia an air channel in the end cap 80, not shown. A check valve andorifice on the interior end of the end-effector provide a slow leakunder pressure and high flow under vacuum, to enable pressure and vacuumto be supplied to any end effector mounted to the cylinder rod.

Extension and retraction of cylinder rod 46 is accomplished by poweringpiston 50. When air is supplied to the extend side of the piston, rod 46extends and when air is supplied to the retract side of the piston, rod46 retracts.

Referring now to FIG. 8, a top view of an actuator as illustrated inFIG. 5, showing the attachment and various connections to the supporttable, pressure and vacuum connectors 92 and 94 are positioned in aportion of the flange of main housing 44 and electrical/businterconnector 96 is positioned between the two connectors 92 and 94.Corresponding connectors are provided at each position of the supporttable so that when an individual actuator is inserted into an opening ofthe support table, the vacuum, pressure and electrical connectors matewith the corresponding connectors at the support table, therebyproviding vacuum, air pressure and electrical supply and commands to theactuator. The air pressure and vacuum connectors at the support tableare self sealing such that when no actuator is present, the air pressureand the vacuum supply are sealed at that connector to prevent loss ofvacuum or air pressure. The actuator is suitably secured to its positionat the support table via four mounting bolts 98 which are spaced in anysuitable pattern to provide appropriate engagement with the supporttable. A hydraulic bleed port 99 is also provided to allow the hydraulicportion of the individual clamping member in a particular actuator to bebled to remove air from the hydraulic system.

The operation of the system described hereinabove in a typicalapplication would entail positioning actuators in the various aperturesof the table portion configuration appropriate to support the part to beworked upon and then adjusting the height of individual actuators toprovide an appropriately shaped support base. FIG. 9 is a flow chartillustrating operational steps for the system. Returning to FIG. 9, thesequence of operation for using the system is as follows: First, allactuators present in the system are retracted to their lowermostposition (step 100). Then, those actuators which are to be used in thecurrent setting are extended to the end of travel, suitably in asimultaneous manner (step 102). In a particular embodiment the extensiondistance of the surface of the table is eight inches, although this isnot a requirement. A machine tool which is being used in conjunctionwith the flexible tooling actuators is then directed to position itselfabove the first actuator (step 104). The machine tool will typicallyhave a flat plate-like attachment thereon and this flat plate-likeattachment is lowered to be in contact with the vacuum cup of theend-effector of the first actuator. Vacuum is then applied to theend-effector by operation of valve 40 of FIG. 7 and simultaneously theextend operation is turned off (by actuation of valve 36) to allow theshaft of the actuator to free float (step 106). The operation of thevacuum then causes the actuator to be sucked up into contact with theflat portion of the machine tool. Next, an appropriate wait period isallowed to pass (step 108), for example, two seconds, for theappropriate seal to be made between the vacuum cup and the machine toolmember. Alternatively, sensing may be provided to determine that contactbetween the machine tool member and the end-effector has beenappropriately made. This sensing may include proximity detection or someother type of contact switch, for example.

Now, with the end-effector (and thereby the actuator) in firm engagementwith the machine tool member, the machine tool is lowered to bring theactuator to the desired height setting (step 110). The locking colletmember 48 of FIG. 6 is activated by operation of valve 38 of FIG. 7,whereupon the shaft of the actuator is firmly locked into position (step112). A time delay may be observed to assure complete locking, forexample one second. Next, the vacuum being supplied is removed, whichcauses air to blow back through the end-effector, providing release ofthe machine tool plate member and the end-effector (step 114). In theparticular embodiment, this operation is performed by activation of aretract command (actuation of valve 40) which does not cause theactuator to retract because the locking member 48 of FIG. 6 is engaged,but instead causes vacuum to be removed. The machine tool then retractsaway from the actuator and proceeds to the next actuator in the sequenceof actuators to be set (decision block 115, step 116). Once arriving atthe next actuator, the setting process is repeated. This processcontinues multiple times until all actuators are set.

Once all the actuators have been set to their desired height, eachsecurement member for the actuators in use is locked and variousactuators are blowing a small volume of air through their end-effectors(block 118). Those actuators which are not being used in the presentconfiguration are all set to the retract state and are also providing asmall volume of air through the end-effector (block 120). The part to beoperated upon is then prepositioned above the support table and adjustedto be engaged by the support members in the appropriate positions. Onceso positioned, the retract valve is turned off (valve 40, FIG. 7) whichcauses vacuum to be applied to the actuators which are in the extendedposition (step 122). Accordingly, the part being operated upon is heldby the suction force as a result of the vacuum and the cup portion ofend-effectors 34. Loading and unloading of subsequent parts to beoperated upon is accomplished by alternating the retract state betweenON and OFF (block 124) which alternates between vacuum being appliedthrough the suction cup of end-effector 34 and air being blown outwardlythrough the suction cup, accordingly holding or releasing the part beingoperated upon.

An individual actuator as illustrated in FIG. 7 employs three valves 36,38 and 40 which suitably comprise spring return single solenoid 3-wayvalves. Valve 36, denoted the extend valve, when in its ON state causesthe actuator shaft to extend and when in its OFF state causes air to bedumped from the extend operation. Valve 38 controls operation of theclamping member of FIG. 6 and when in an ON state causes the clamping tooccur and when in an OFF state removes clamping to allow the actuator toextend or retract freely. Valve 40 controls retraction (the retractvalve). When in the on state, valve 40 causes the actuator to retractand also allows air to bleed through the end-effector, while in the OFFstate causes vacuum to be applied to the back of the actuator and pullsvacuum through the end-effector. In a particular embodiment, each valveis a 24 volt DC solenoid. The state of the various valves during theoperation described hereinabove with reference to FIG. 9 is illustratedin Table 1.

                  TABLE 1                                                         ______________________________________                                        Step    Valve 36      Valve 38 Valve 40                                       ______________________________________                                        100     OFF           OFF      ON                                             102     ON            OFF      OFF                                            104     ON            OFF      OFF                                            106     OFF           OFF      OFF                                            108     OFF           OFF      OFF                                            110     OFF           OFF      OFF                                            112     OFF           ON       OFF                                            114     OFF           ON       ON                                             116     OFF           ON       ON                                             118     OFF           ON       ON                                             120     OFF           OFF      ON                                             122     OFF           ON       OFF                                            124     OFF           ON       ON/OFF                                         ______________________________________                                    

Referring now to FIG. 10, a side partially cutaway view of an activeactuator system according to the present invention, the features andoperation thereof will be described. Operation and structure of somecomponents of the active actuator system correspond to similarcomponents of the passive actuator system. The active actuator system200 is employed in conjunction with a table 202 which corresponds to thetable 12 of the passive actuator embodiment described hereinbefore andincludes an actuator well 204 which receives the actuator therein andmay include a seal 206 to keep contaminants from entering below thetable and contaminating components of the actuator. An end effector 208is positioned at the end of the actuator body and in the illustration ofFIG. 10 employs a swivel head vacuum clamp member. The active systemcomprises a number of main components, including clamp body 210 which isoperative to clamp and unclamp a stroke rod 212, for holding the strokerod in a desired position as well as for halting upward or downwardmovement of the stroke rod at a precise position. An actuator cylinderbody member 214 supports the stroke rod 212 as well as the variousplumbing and electrical members as discussed herein. A top view isprovided of the cylinder body member 214, which is suitably formed as anextrusion and then cut to the desired length (determined by the strokelength of the actuator), in FIG. 11 and is discussed hereinbelow. Alinear transducer 216 is provided within the actuator system toaccurately describe the current extended position of the stroke rod,while mounted therebelow is an intensifier 218 which operates in acorresponding manner to the intensifier described hereinbefore withreference to FIG. 7. The intensifier thus employs a relatively lowpressure pneumatic supply to intensify a relatively small volume ofhydraulic fluid, e.g. oil, to provide a high pressure clamping force forthe clamp body 210. Mounted below the intensifier is valve andcontroller body 220 which includes solenoid valves for switching theflow of pneumatic and hydraulic supply for directing the up-and-down andclamp-and-unclamp operations of the system. A controller is alsoprovided which receives commands from a central control over a network(see FIG. 16) to position the stroke rod to the desired height foroperation and governs operation of the solenoids to accurately positionthe actuator. The system also includes an oil reservoir 222 which storesthe hydraulic fluid and which also, as governed by speed valve 226,enables a flow rate to be modified to change the speed at which thestroke rod 212 extends or retracts.

Referring now to FIG. 17, a pneumatic/hydraulic diagram illustrating thevarious circuits thereof which enable extension and retraction of theactuator, the operation thereof will now be described. Referring to FIG.17, the system comprises a pneumatic supply line 270 which supplies airunder pressure, a vacuum supply line 272 which supplies vacuum and anexhaust line 274 which exhausts air pressure as appropriate duringoperation. A muffler 275 may also be included on the exhaust line tomuffle exhaust noise. The vacuum and air pressure lines 272, 270 aresuitably provided as noted hereinabove to an operational table whereinan individual actuator connects via a coupling to each of the vacuum andpressure supplies. The pressure supply line 270 is further connected tovarious solenoids, including the retract and speed control solenoid 276,the vacuum/pressure solenoid 278, the extend solenoid 280 and theintensifier solenoid 282. From the other side of solenoid 276, airpressure is supplied to oil reservoir/accumulator 222 via accumulatorpressure line 284. Air pressure from vacuum/pressure solenoid 278 isfurther provided to the extend solenoid 280 and air pressure as outputby solenoid 280 is provided by rod extension line/actuator vacuum line288 to the actuator for governing extension thereof. Intensifiersolenoid 282 supplies air pressure to the extend side of the extend sideof the intensifier circuit via intensifier extend line 290. A returnspring 286 causes the intensifier to retract in the absence of extensionpressure. Vacuum is distributed by solenoid 278, as further suppliedthrough solenoid 280 and supplied as rod extension line/actuator vacuumline 288 to the actuator system. Vacuum is also supplied to vacuumpressure transmitter 294 which detects an existence of vacuum, forcontrol system logic and the like.

Each actuator unit, which as noted hereinbefore is adapted for insertionand removal at individual sites on a table and essentiallyself-contained, includes its own self-contained hydraulic system whichsuitably employs oil as a hydraulic fluid. The hydraulic system includesboth a high pressure hydraulic system 296 illustrated in bold lines inFIG. 17 and a low pressure hydraulic system illustrated in semi-boldlines 298. Pressure for the high pressure hydraulic system is generatedby the intensifier circuit 218 wherein the high pressure is supplied tothe clamp body 210 for controlling clamping as discussed hereinbelow.The low pressure oil system is supplied by oil reservoir 222, pressurebeing generated by air pressure line 284, and is further connected to afill check valve 300, with the high pressure oil system also connectedto the check valve. Accordingly, since the high pressure system operateson a very small oil volume, while the low pressure system employs a muchgreater oil volume, the accumulator/oil reservoir 222 is suitably ableto resupply oil to the high pressure system via the check valve. Sincethe high pressure system is not always at high pressure, but only duringcertain clamp operations as discussed hereinbelow, when the highpressure side is at a low pressure, oil from the accumulator is allowedto resupply the high pressure side via the check valve. However, thecheck valve prevents the high pressure circuit oil from travelingbackwards to the low pressure side. Thus, the individual actuator issomewhat self-contained and only need be resupplied with oil (viareplenishing of the oil reservoir 222) on rare occasions or duringroutine, infrequent maintenance. The low pressure side includes a speedcontrol valve 302, corresponding to valve 226 of FIG. 10, which furtherconnects the low pressure system to a dampening system 304 which isoperative to provide extend/retract dampening. In operation, the speedcontrol valve 302, as directed by the valve controller circuitry 220, iseither in a high or low flow speed mode. In the high flow speed mode,the oil is able to relatively freely flow between the accumulator andthe dampening volume space 304. However, in the low speed position,since the valve is ground to provide a precise known leak rate, thetransfer of oil between the accumulator and the dampening space is at aslower rate. Accordingly, the actuator extends at a much slower rate.Any contamination which may collect in speed valve 302 during its slowor closed state is suitably swept away when the valve opens to its highspeed state, effectively flushing the valve and preventing its becomingclogged by buildup of contaminants.

As also mentioned herein with reference to FIG. 10, the active actuatorsystem includes a linear transducer 306 therein which, in conjunctionwith annular magnet 308 and circuit board 310, generates a positionsignal provided to the controller. The magnet 308 extends and retractsalong the length of transducer 306, generating a signal which isinterpreted by circuit board 310 to indicate the position of the magnet.Since the magnet is secured to the actuator piston, it thus indicatesthe amount that the piston is extended. The transducer, magnet andaccompanying circuit board are preferably manufactured by BalluffIncorporated of Germany.

In operation, the system causes extension and retraction of the actuatorcylinder by appropriate operation of the solenoids and subsequentapplication of vacuum or air pressure. The extension is controlledsomewhat by the dampening circuitry 304 wherein as the rod extends, thevolume of area 304 is reduced and excess oil is displaced through speedcontrol valve 302 into accumulator 222. The extension speed is governedprecisely by whether the speed control valve is in its fully openposition or in the closed/controlled leak position. In the preferredembodiment, retract is always at the fast flow rate. Thus, in operation,the actuator is extended a substantial distance at high speed and then,when within for example one-half inch of its final destination, valve302 is operated to switch to slow speed, whereupon once the desiredlocation is reached, then solenoid 282 is operated so as to cause theintensifier to retract, reducing the oil pressure in the high pressureoil line 296 which thus allows the clamping member to relax to itsclamped position, securing the actuator rod at its desired position.

The clamping member comprises a hydraulic collet in interference fitwith the extension rod (0.0015 inches). The collet is mildly heated to,for example, 300 degrees, to initially slip it onto the shaft. O-ringson the inside of the collet at both ends enable introduction of highpressure oil to the inside of the collet. A pair of O-rings on the outerdiameter with a hole through to the inner diameter provide the path infor the oil. Applied pressure expands the collet, with the normal stateof the collet locked. Alternatively, a normally unlocked collet may beused as previously described.

When movement of the rod is desired, then the intensifier is caused toextend, thereby raising the oil pressure in line 296 which causes theclamp member to expand outwardly thus enabling the actuator to moveupwardly or downwardly, since the clamp member is in an interference fitwith the rod during those times at which the intensifier is notsupplying pressure to the high pressure oil line. Once the actuator rodis appropriately positioned, a determination may be made via a lineartransducer whether the rod actually was positioned within a desiredtolerance range. If desired, it is possible in accordance with thepresent invention to unclamp the rod and then reposition. Positioningaccuracy is further enhanced by calibration on an occasional basis, todetermine the time required for clamping to be effective. Thus, tocalibrate the system, the actuator is caused to move (suitably at lowspeed, for increased accuracy) and the clamp command is given whilesimultaneously measuring the actuator's position as reported by thelinear transducer. Then, the final position of the actuator is read fromthe transducer after the actuator stops moving and the differencebetween the position when the clamp command was given and the actualclamped position is determined and factored in for future clampingcommands, so that the clamp command is given at the appropriate time.

Once clamped in position, then vacuum may be supplied by operation ofsolenoids 278 and 280 wherein a check valve is provided to the interiorof the piston rod so as to provide vacuum up through the center thereofto the end effector as desired for securing via suction, any workpiecebeing secured against the end effector.

The intensifier operates in a manner corresponding to that as discussedhereinabove with reference to FIG. 7, in the passive embodiment.

Referring now to FIG. 11, which is a top view of the cylinder body ofthe actuator of FIG. 10, it may be observed that in cross section theactuator body is somewhat annular in configuration with the addition ofthe oil reservoir 222. About the periphery of the cylinder body are aseries of openings 228 which are provided to pass electrical cables andair/vacuum/oil tubes along the extent of the body. Four openings 230 areprovided to receive fasteners for securing other pieces of the systemthereto.

Referring now to FIG. 12, which is a top view of the interface portion224 of a table which receives and connects with an individual actuator,the air pressure is provided via a coupling 232 while vacuum is providedto coupling 234. Both couplings are connected to respective pneumaticand vacuum supplies which are suitably provided at each position on thetable suitable for receiving an actuator therein. The couplings arenormally closed when not connected to an actuator such that no air orvacuum leak occurs in table positions which do not have actuators placedtherein. An electrical interface 236 is also provided and suitablyprovides ground, power, and twisted pair communication for RS-485 orother multi-drop network communication standard. Correspondingconnectors are provided on the actuator which mate with couplings 232and 234 and electrical connector 236 such that when the actuator ispositioned and lowered into the table, couplings 232 and 234 andconnector 236 interconnect with their corresponding parts on theactuator itself. Both connectors 234 and 232 as well as the electricalinterface 236 are mounted in a "floating" fashion such that longitudinaland lateral movement is allowed (X-Y) to accommodate slight misalignmentas the actuator is inserted into the table. This ensures that theactuator does not bind or become misaligned so as to damage theconnector or not properly seat in the table. An addressing means 240 isalso provided, which in the illustrated embodiment comprises an eightposition DIP switch. The address of the individual table position isaccordingly set by operation of the switches on the DIP switch.Accordingly, the RS-485 address of this particular table position may beuniquely set at installation time. Thus, an actuator may be moved fromany position on the table to any other position on the table without theneed for reprogramming of the actuator, since each individual tableposition has its own unique address. The RS-485 standard enables up to256 addresses on an individual bus. Since a particular application ofthe present invention employs up to 1200 or more table positions,multiple hubs are employed, each hub having no more than 256 individualtable positions addressed thereon.

Referring now to FIG. 13, which is a side view of the table insertposition of FIG. 12, partially cut away taken along line 13--13 of FIG.12, the position of air connector 232 may be observed as well aselectrical connector 236. Pneumatic supply to connector 232 is providedvia a pneumatic hose 240 which is supplied by an external pneumaticsupply source. A dowel portion 242 is provided at the table position andextends upwardly a distance above the plane of the position and providesan alignment pin for engaging the actuator (which has a correspondingrecess) as it is lowered onto the table position, assisting in guidingthe actuator to the proper seating thereof.

Referring now to FIG. 16, which is a block diagram of a particulararchitecture employed in controlling the operation of a system accordingto the present invention, each individual actuator has its own dedicatedcontroller 244 with other controllers for other actuator positionsdesignated 244', 244". Since a given system may employ many actuators,each with its own controller, hundreds of controllers may exist on thenetwork, with up to 256 on each individual network hub. One network hubis illustrated (246) in the embodiment of FIG. 16. Referring again to anindividual embedded actuator controller 244, connected thereto are thevalves, transducer and the ability for any other I/O device as needed.As noted hereinbefore, each embedded actuator controller 244 isconnected to a network hub 246, wherein plural network hubs 246 areinterfaced with a personal computer based controller 248 which includesmonitor and keyboard 250 for directing operation of the system. The PCcontroller 248 is further suitably interfaced with, for example, a CNCcontroller 252 which is operative to direct a machine tool or the liketo perform operations on the workpiece being held by the flexibletooling system of the present invention. Since each RS-485 networkallows a maximum of 256 separate addresses, the PC controller 248 isprogrammed to know that, for example, the multiple network hubs areconfigured as banks of up to 256 positions each, such that, for example,actuator position number 741 on a given table would be on network hub 3,for example. Accordingly, any command to that position of the tablewould be sent to network hub 3.

Referring now to FIGS. 14 and 15, which comprise side and top viewsrespectively of an extension attachment which allows spacing of anactuator intermediate between two fixed locations, it will be observedthat, in the preferred embodiment, a table has a series of fixed spacedlocations which are adapted to receive actuators therein. However, it ispossible that a particular application might require extra supportbetween two given fixed table locations. Accordingly, referring to FIG.14, an extender attachment includes first and second arm portions 254and 256, wherein the first arm extension fits in engaging relation overa given actuator 258 above the table 202. The attachment is via abayonet type mount which fits over the actuator piston body as extended.The first arm 254 extends from the actuator position to which attachmentis made to an adjacent actuator and includes a clamp 260 which issecured and loosened by a tightening arm 262. Referring to FIG. 15, theclamp portion 260 includes a slot portion 262 which fits over theadjacent actuator and a finger portion 264 which, when tightened byoperation of arm 262, provides a brace against rotation of the armportion 254, so that the position of the extended actuator head isprecisely maintained. Positioned every 22.5 degrees in the illustratedembodiment are locator holes 265, formed in the top of arm portion 254.The corresponding arm portion 256 has a cam lock expanding locating pin257 which is adapted to mate with the corresponding hole 265 and, uponturning of a tightening lever, securely engaging the locating pin withits respective radial hole. Arm portion 256 includes three separatereceiving positions 255, 255' and 255" which are spaced successivelyfurther from the mount position of the extender arm providing threeseparate radial locations along which an end effector may be positionedas illustrated in FIG. 15, every 22.5 degrees. Each individual site 255also provides vacuum supply to the end effector and includes a checkvalve to prevent vacuum leak when that individual site is not in use.

An advantage provided by the flexible tooling system is that the supporttable need not be fully populated with actuators, since the actuatorsmay be moved to different positions on the support table. Accordingly,the system flexibility is high, enabling multiple configurations, whilenot requiring the expense of fully populating the table. Further, eachactuator is essentially self contained, requiring only air, vacuum andelectrical supply as well as instruction data. No external oil lines arerequired as the oil system is fully self contained. The construction isfree from servo type components, allowing low current consumption, whichsimplifies the electrical supply demands made by a table populated witha large number of actuators.

While plural embodiments of the present invention have been shown anddescribed, it will be apparent to those skilled in the art that manychanges and modifications may be made without departing from theinvention in its broader aspects. The appended claims are thereforeintended to cover all such changes and modifications as fall within thetrue spirit and scope of the invention.

We claim:
 1. A dynamic tooling system comprising:a support table havinga plurality of receiving positions thereon, ones of said receivingpositions including a quick-change interface providing a pneumaticsupply and an addressable bus interconnection; and an actuator mechanismadapted to be received in at least one of said plurality of receivingpositions and for interfacing with said interface and extending andretracting as powered by said pneumatic supply in response to commandsreceived via said addressable bus interconnection.
 2. A dynamic toolingsystem according to claim 1 wherein said interface further comprises avacuum supply, and wherein said actuator mechanism supplies vacuum to aportion of said actuator mechanism via said interface in response tocommands received via said addressable bus interconnection.
 3. A dynamictooling system according to claim 1 wherein said actuator mechanismcomprises piston means having an extend side and a retract side, andvalve means operative in response to commands received via saidaddressable bus interconnection for directing said pneumatic supply tothe extend side of said piston means or to the retract side of saidpiston means to effect extension or retraction of said actuatormechanism as directed by said commands.
 4. A dynamic tooling systemaccording to claim 1 wherein said actuator mechanism comprises lockingmeans for locking said actuator in a current position and valve meansoperative in response to commands received via said addressable businterconnection for directing said locking means to be in either alocked state or an unlocked state.
 5. A dynamic tooling system accordingto claim 1 wherein said actuator mechanism comprises a normally lockedlocking means for locking said actuator in a current position.
 6. Adynamic tooling system according to claim 5 wherein said normally lockedlocking means comprises a collet member in interference fit with anextensible portion of said actuator mechanism.
 7. A dynamic toolingsystem according to claim 6 further comprising a hydraulic system forhydraulically expanding said collet member to relieve the interferencefit with the extensible portion of said actuator mechanism, therebyenabling said extensible portion to extend or retract.
 8. A dynamictooling system according to claim 1 further comprising damping means forgoverning the extension/contraction speed of said actuator mechanism. 9.A dynamic tooling system according to claim 8 wherein said damping meanscomprises speed control means for providing at least two governingspeeds to said actuator mechanism.
 10. A dynamic tooling systemaccording to claim 1 further comprising a hydraulic system whichcomprises a relatively low volume/high pressure side and a relativelyhigh volume/low pressure side and further comprising resupplying meansfor resupplying hydraulic fluid to the high pressure side from the lowpressure side.
 11. A dynamic tooling system comprising:a support tablehaving a plurality of apertures therein; pneumatic supply for providingpneumatic pressure at a plurality of positions at said support table;vacuum supply for providing vacuum at a plurality of positions at saidsupport table; bus means for providing data and electrical supply at aplurality of positions at said support table; and an actuator mechanismadapted to be removably received within at least one of said pluralityof apertures, skid actuator mechanism comprising:a quick-changeinterface that provides one-step engagement of the actuator with thesupport table; an extensible member; a collet means for clamping saidextensible member in a given position; hydraulic means for effectingclamping and unclamping of said collet means; a hydraulic intensifierdriving said hydraulic means; pneumatic means for driving said hydraulicintensifier, and providing clamp/unclamp control to said collet means;and valve means directing application of said pneumatic means inresponse to data provided by said bus means.
 12. A dynamic toolingsystem comprising:a support table having a plurality of aperturestherein; pneumatic supply for providing pneumatic pressure at aplurality of positions at said support table; vacuum supply forproviding vacuum at a plurality of positions at said support table; busmeans for providing data and electrical supply at a plurality ofpositions at said support table; and an actuator mechanism adapted to beremovably received within at least one of said plurality of apertures,said actuator mechanism comprising:an extensible member; a collet meansfor clamping said extensible member in a given position; hydraulic meansfor effecting clamping and unclamping of said collet means; a hydraulicintensifier driving said hydraulic means; pneumatic means for drivingsaid hydraulic intensifier, and providing clamp/unclamp control to saidcollet means; valve means directing application of said pneumatic meansin response to data provided by said bus means; and second valve meansoperative in response to data provided by said bus means for providingpneumatic pressure to an extend side or a retract side of saidextensible member as dictated by said data for causing said extensiblemember to extend or retract.
 13. A dynamic tooling system according toclaim 11 further comprising adapter means for attachment to saidactuator mechanism as positioned in one of said plurality of apertures,said adapter means providing an end effector intermediate between saidone of said plurality of apertures and an adjacent aperture thereto. 14.A dynamic tooling system according to claim 11 wherein said hydraulicintensifier drives said hydraulic means via an internal supply channelin a body of said actuator mechanism, thereby reducing likelihood ofleaking as no external plumbing is employed.
 15. A dynamic toolingsystem according to claim 4 wherein said locking means compriseshydraulic locking means and wherein hydraulic fluid is supplied theretovia an internal supply channel in a body of said actuator mechanism,thereby reducing likelihood of leaking as no external plumbing isemployed.
 16. A dynamic tooling system according to claim 1 wherein saidactuator mechanism includes an actuator interface that releasably snapsonto the interface of said one of said receiving positions so as toprovide one-step engagement of the actuator with the support table. 17.A dynamic tooling system according to claim 1 wherein said interfaceincludes an addressing unit.
 18. A dynamic tooling system comprising:asupport table having a plurality of receiving positions thereon, ones ofsaid receiving positions including an interface providing a self sealingpneumatic supply and an addressable bus interconnection, said selfsealing pneumatic supply self sealing upon removal of an actuatormechanism from said one of said receiving positions; and an actuatormechanism adapted to be received in at least one of said plurality ofreceiving positions and for interfacing with said interface andextending and retracting as powered by said pneumatic supply in responseto commands received via said addressable bus interconnection.
 19. Adynamic tooling system comprising:a support table having a plurality ofreceiving positions thereon, ones of said receiving positions includingan interface providing a pneumatic supply and an addressable businterconnection; and an actuator mechanism adapted to be received in atleast one of said plurality of receiving positions and for interfacingwith said interface and extending and retracting as powered by saidpneumatic supply in response to commands received via said addressablebus interconnection, wherein said actuator mechanism includes a lineartransducer.